JP3731696B2 - Cooling device for water-cooled internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling device for a water-cooled internal combustion engine having a relatively small displacement, particularly a water-cooled internal combustion engine mounted on a small vehicle such as a motorcycle.
[0002]
[Prior art, problems to be solved]
A cam shaft for driving the valve mechanism of the internal combustion engine is disposed on the cylinder head. The cam shaft is rotationally driven by the crankshaft through the transmission mechanism, and is rotated outward by the camshaft from the transmission mechanism. A water-cooled internal combustion engine provided with a driven cooling water pump is conceivable.
[0003]
In this configuration, when forming a communication path for guiding the internal combustion engine cooling water discharged from the cooling water pump to the water jacket formed in the cylinder block or cylinder head, the flow path length is shortened as much as possible to reduce the passage resistance. In addition, it is desirable that the number of parts and the number of processing steps be reduced.
[0004]
Conventionally, a cooling water passage is formed inside a support shaft that supports an idler pulley for a timing belt of a water-cooled internal combustion engine, thereby, compared to the case where these support shaft and cooling water passage are formed separately, the number of parts, Although there is one with a reduced processing man-hour (see Japanese Utility Model Publication No. 4-52526), no particular consideration is given to the arrangement relationship between the cooling water passage and the cooling water pump.
[0005]
[Means for solving the problems and effects]
The invention of the present application relates to a cooling apparatus for a water-cooled internal combustion engine that solves the above-described problems, and the invention described in claim 1 includes a camshaft for driving a valve mechanism of the internal combustion engine on the cylinder head. water-cooled but is arranged, wherein the cam shaft is rotated via a more transmission mechanism crankshaft, equipped with a cooling water passage through which cooling water flows by a cooling water pump drive outside of the transmission mechanism compartment including the transmission mechanism in the cooling system of an internal combustion engine, a communicating pipe extending from said cooling water passage in the internal combustion engine body, the disposed so that entrained transmission mechanism chamber, wherein the outer peripheral portion of the communicating tube, to said transmission mechanism A cooling device for a water-cooled internal combustion engine, characterized in that an idle pulley to be hooked is rotatably fitted and supported .
[0006]
Since the invention described in claim 1 is configured as described above, since the communication pipe is used as the rotation support shaft of the idle pulley, a member for rotationally supporting the idle pulley can be omitted. That is, a communication pipe that traverses the transmission mechanism chamber can be realized without increasing the number of parts. Thereby, the processing man-hours such as shaft hole processing required when separately manufacturing the rotation support shaft and the communication pipe of the idle pulley can be greatly reduced.
[0007]
Further, in the invention described in claim 2, the support shaft of the idle pulley of the endless transmission mechanism has a communication passage in which a passage of cooling water is formed to form a passage spanned in the endless transmission mechanism chamber. Since the pipe can also be used, the number of parts and the number of processing steps are reduced, the manufacture of the cooling device for the water-cooled internal combustion engine is facilitated, and the cost can be reduced. Furthermore, since the cooling pump and the cooling water passage are arranged in the region surrounded by the transmission mechanism, the length of the connecting pipe between the cooling pump and the cooling water passage can be shortened, and the passage resistance can be further reduced. Reduction can be achieved.
[0008]
The invention described in claim 3 can increase the winding width of the endless chain to some extent by the idle pulley, and by securing the idle pulley in the vicinity of the communication pipe, the space for arranging the communication pipe can be secured. Becomes easier.
[0009]
Furthermore, in the invention described in claim 4, the communication pipe forming the passage spanned over the transmission mechanism chamber can be formed at a time by casting integrally with the partition wall of the magnet coupling type cooling water pump. The formation is facilitated, the number of parts is further reduced, and the manufacture of the cooling device for the water-cooled internal combustion engine is facilitated.
According to a fifth aspect of the present invention, there is provided a passage that extends over the transmission mechanism chamber using the partition wall of the magnet coupling type cooling water pump and the wall surface of the cylinder head that face each other across the transmission mechanism chamber. Can be firmly supported.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment (Embodiment 1) of the invention according to claims 1, 2 and 4 of the present application shown in FIGS. 1 to 6 will be described below.
FIG. 1 is a perspective view schematically showing a water-cooled internal combustion engine to which a cooling apparatus for a water-cooled internal combustion engine according to Embodiment 1 is applied, and is an overhead valve type 4-stroke cycle (commonly called 4 cycles) single-cylinder water-cooled type. The internal combustion engine 1 is mounted on a vehicle body of a small motorcycle (not shown) so as to be positioned between the front and rear wheels.
[0011]
The water-cooled internal combustion engine 1 includes left and right crankcases 2 and 3, a cylinder block 4, a cylinder head 5, and a cylinder head cover 6, and a cylinder of the cylinder block 4 is disposed at the front ends of the crankcases 2 and 3. The internal combustion engine main body 1a and the cylinder head cover 6 formed by integrating the cylinder block 4 and the cylinder head 5 are sequentially stacked so that the central axis of the hole 7 faces substantially horizontally forward. These crankcases 2, 3 and cylinder block 4. The cylinder head 5 and the cylinder head cover 6 are integrally coupled to each other.
[0012]
3 and 4, a piston 8 is slidably fitted in the cylinder hole 7, and a crankshaft 9 is pivotally supported by the left and right crankcases 2 and 3, Both ends of a connecting rod 12 are pivotally attached to the piston 8 and the crankshaft 9 via a piston pin 10 and a crankpin 11, and when the piston 8 reciprocates, the crankshaft 9 is driven to rotate. It is like that.
[0013]
An intake port 14 and an exhaust port 15 communicating with the combustion chamber 13 at the top of the cylinder hole 7 are formed in the cylinder head 5, and an intake valve 16 and an exhaust valve 17 are respectively connected to the intake port 14 and the exhaust port 15. It is provided so that it can be opened and closed.
[0014]
A camshaft (camshaft) 18 is disposed adjacent to the top ends of the intake valve 16 and the exhaust valve 17, and the camshaft 18 is sandwiched between the cylinder head 5 and the camshaft holder 20 via a bearing 19 and is freely rotatable. The driven sprocket 21 is integrally fitted to the left end enlarged portion 18a of the camshaft 18, and the endless chain (transmission mechanism) 23 is connected to the drive sprocket 22 and the driven sprocket 21 integrated with the crankshaft 9. The camshaft 18 is driven to rotate at half the rotational speed of the crankshaft 9, and the intake valve 16 and the exhaust valve 17 are opened and closed once each time the crankshaft 9 rotates twice. It is designed to be driven.
[0015]
Further, as shown in FIGS. 2, 5, and 6, a radiator 30 that is a heat radiating portion of a cooling device that cools the water-cooled internal combustion engine 1 is disposed above the cylinder block 4. The cooling water tanks 31 and 32 on both sides (the left and right sides are reversed in FIG. 5), the flat radiating fins 33 arranged in parallel in the longitudinal direction and along the vertical plane, and the cooling water tanks 31 and 32 A cooling water conduit 34 (circularly arranged in three rows in the vertical direction and two rows or three rows in the front-rear direction) that passes through the opposing inner wall and the radiating fin 33 in the horizontal direction of the vehicle width. A cooling water inlet / outlet opening 35 is formed in the bottom surface 31a of the tanks 31 and 32 (shown in FIG. 6 and the bottom surface of the cooling water tank 32 is not shown), and a flange 36 integral with the bottoms of the cooling water tanks 31 and 32 is formed. , 37 and screwed into radiator support portions 40 and 41, which will be described later. The bolt 47 is firmly attached to the cylinder block 4. A connection sleeve 38 is fitted into the cooling water access opening 35 so as to protrude downward. A cap 39 is detachably fitted to the top of the cooling water tank 31.
[0016]
Further, as shown in FIG. 3, the cylinder block 4 is provided with radiator support portions 40, 41 integrally projecting from the left and right sides, and a cooling water passage 42 provided in the radiator support portions 40, 41, 43, the right cooling water passage 43 communicates with a cylindrical cooling water jacket 44 that surrounds the outer periphery of the combustion chamber 13, and the cylinder head 5 also has a cooling water jacket 45 that matches the open end of the cooling water jacket 44. These cooling water jackets 44 and 45 are formed in a tapered shape in cross section from the mating surface of the cylinder block 4 and the cylinder head 5 to the back. The cooling water passage 42 on the left side has a lower end of a connection sleeve 38 fitted into the upper opening thereof, and is connected to the cooling water tank 31 via the connection sleeve 38.
[0017]
Further, as shown in FIGS. 3 and 4, the central portion of the left end enlarged diameter portion 18a of the camshaft 18 is removed from the end surface to form a recess 18b, and a plurality of portions are formed on the inner peripheral surface of the recess 18b. A cylindrical permanent magnet 24 having a pole is disposed. Instead of this, a plurality of permanent magnets may be arranged at equal intervals in the circumferential direction.
[0018]
The cooling water pump 50 that is rotationally driven by the camshaft 18 includes a partition wall (pump casing) 51, a pump cover 52, and the partition wall 51 and the pump cover 52 in the rotor storage part 51a of the partition wall 51 via the rotation shaft 53. The impeller 54 is rotatably supported by the impeller 54. On the outer peripheral surface of the shaft portion 54a of the impeller 54, the number of poles relative to the permanent magnet 24 of the camshaft 18 is provided via the rotor storage portion 51a of the partition wall 51. A cylindrical permanent magnet 55 is fitted, and the impeller 54 of the cooling water pump 50 is magnetically coupled to the camshaft 18 by the permanent magnets 55, 24, and the impeller corresponds to the rotation of the camshaft 18. 54 is driven to rotate.
[0019]
As shown in FIG. 6, the suction portion 56 of the cooling water pump 50 communicates with the lower opening 42 a of the cooling water passage 42 of the left radiator support portion 40 through the communication pipe 46, as shown in FIGS. 3 and 4. As shown in the drawing, the discharge portion 57 of the cooling water pump 50 is communicated with a discharge passage 58 (formed by being closed by the partition wall 51) of the pump cover 52, and the communication of the partition wall 51 communicating with the discharge passage 58 is performed. Both ends of the communication pipe 61 are water-tightly fitted into the passage 59 and the communication passage 60 communicating with the cooling water jacket 45 of the cylinder head 5, and the cooling water in the left cooling water tank 31 of the radiator 30 is The cooling water sucked into the cooling water pump 50 through the cooling water passage 42, the communication pipe 46, and the suction portion 56 of the left radiator support portion 40 and pressurized by the impeller 54 of the cooling water pump 50 is discharged to the discharge portion 57. From the discharge passage 58, the communication passage 59, the communication pipe 61 and the communication passage 60 through the cooling water jacket 45, cooling The water jacket 44 is discharged.
[0020]
The communication pipe 61 is fitted into a hole 63 formed in an outer peripheral wall of a cylinder head 5 surrounding a transmission mechanism chamber 62, which will be described later, and further, its tip is inserted into the communication path 60 and is axially driven by a pump partition wall 51. Movement is restricted, and is prevented from falling out.
[0021]
As shown in FIGS. 3 and 4, an idler sprocket (idle pulley) 25 that meshes with the endless chain 23 is rotatably fitted on the outer periphery of the communication pipe 61. An idler sprocket 27 is pivotally attached to the cylinder block 4 via a pin 26 at a position close to 9, and an endless chain 23 is sandwiched from above and below near the crankshaft 9 as shown in FIG. The idler sprockets 28 and 29 are pivotally attached.
[0022]
As shown in FIG. 6, the communication pipe 61 is disposed in the transmission mechanism chamber 62 in which the endless chain 23 is accommodated, and in the region surrounded by the travel path of the endless chain 23. The idler sprocket 25 fitted on the outer periphery of the communication pipe 61 is also disposed in the same region. As a result, the idler sprocket 25 meshes with the endless chain 23 from the inside of the travel path of the endless chain 23. It is like that.
[0023]
Since the first embodiment is configured as described above, the water-cooled internal combustion engine 1 is in an operating state, and the cooling is magnetically coupled to the camshaft 18 that rotates in response to the operation of the water-cooled internal combustion engine 1. When the impeller 54 of the water pump 50 is driven to rotate, the cooling water in the left-side cooling water tank 31 cooled by the radiator 30 passes through the cooling water inlet / outlet opening 35 to the connection sleeve 38 and the cooling water passage 42 of the radiator support 40. And the suction pipe 56 of the cooling water pump 50 through the communication pipe 46, and after being pressurized by the impeller 54 of the cooling water pump 50, from the discharge part 57 of the cooling water pump 50, the discharge passage 58, the communication path 59, discharged to the cooling water jackets 45 and 44 through the communication pipe 61 and the communication passage 60, and the cooling water in the cooling water jackets 45 and 44 is cooled on the right side from the cooling water passage 43 of the right radiator support portion 41. It is sent into the water tank 32 and passes through the cooling water conduit 34 to cool the left Returning to the tank 31, the cooling water circulates in the cooling water system.
[0024]
When a small motorcycle (not shown) travels, the traveling wind traveling from the front to the rear passes between the radiation fins 33 of the radiator 30 and is heated by the heated cooling water flowing in the cooling water conduit 34. The cooling water 33 is radiated by the traveling wind, and the cooling water in the cooling water conduit 34 is cooled by the heat radiation of the radiating fins 33.
[0025]
The communication pipe 61 is disposed in the transmission mechanism chamber 62 in which the endless chain 23 is accommodated, and in the region surrounded by the travel path of the endless chain 23. The cooling water pump 50 and the cooling water jacket 45 of the cylinder head 5 are disposed at positions that can be arranged in parallel and can be arranged so as to be in contact with the outer wall surface of the cylinder head 5 surrounding the combustion chamber 13 substantially perpendicularly. Can be connected in the shortest distance. Thereby, the flow path length of the cooling water system can be further shortened, the passage resistance can be reduced, and the power consumption of the cooling water pump 50 can be reduced.
[0026]
Further, the communication pipe 61 is fitted into a hole 63 formed in the outer peripheral wall of the cylinder head 5 surrounding the transmission mechanism chamber 62, and its tip is inserted into the communication path 60, and is axially moved by the pump partition wall 51. Since the movement is restricted and the retaining is made, the reliability of the cooling device of the water-cooled internal combustion engine 1 is improved.
[0027]
Further, since the communication pipe 61 is used as a pivot member for the idler sprocket 25, a member for pivotally supporting the idler sprocket 25 can be omitted. In other words, the communication pipe 61 that traverses the transmission mechanism chamber 62 can be realized without increasing the number of parts. As a result, the number of processing steps such as shaft hole processing required when the pivot member and the communication pipe 61 of the idler sprocket 25 are manufactured separately can be greatly reduced.
[0028]
Next, an embodiment (Embodiment 2) of the third aspect of the present invention illustrated in FIG. 7 will be described.
In the second embodiment, the communication pipe that forms a passage spanning the transmission mechanism chamber 62 is integrally formed with the partition wall 51 of the magnet coupling type water pump 50 by casting, and the communication pipe 61 in the first embodiment is used. It is not formed as an independent part. Then, the base end portion of the communication pipe equivalent portion 64 of the integrally molded product is fitted into a hole 63 formed in the outer peripheral wall of the cylinder head 5 surrounding the transmission mechanism chamber 62, and one end of the integrally molded product is It is supported.
Although the above points are different from the first embodiment, the other points are not different from those of the first embodiment, and thus detailed description thereof is omitted.
[0029]
Since the second embodiment is configured as described above, the communication pipe that forms the passage spanning the transmission mechanism chamber 62 is integrated with the partition wall 51 of the magnetic coupling water pump 50 at a time by casting. It can be formed and its formation is facilitated. Further, the number of parts is further reduced, and the manufacturing of the cooling device for the water-cooled internal combustion engine 1 is further facilitated.
[0030]
In the first embodiment and the second embodiment, the cooling water pump 50 is a magnet coupling type cooling water pump. Instead of this, a normal type cooling water pump directly driven by the camshaft 18 is used. In this case, the camshaft 18 directly drives the cooling water pump disposed outside the endless chain 23 through the pump casing of the normal type cooling water pump. .
One end of the communication pipe that forms a passage spanning the transmission mechanism chamber 62 is supported by the pump casing of the normal type cooling water pump, or is formed integrally with the pump casing by casting.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a water-cooled internal combustion engine to which a cooling device for a water-cooled internal combustion engine according to an embodiment (Embodiment 1) of claims 1, 2 and 4 of the present application is applied. is there.
FIG. 2 is a right side view of FIG.
3 is a cross-sectional plan view cut along line III-III in FIG. 2;
4 is a partially enlarged view of FIG. 3;
FIG. 5 is a front view with a part cut away, taken along line V in FIG. 2;
6 is a partially cutaway left side view of FIG. 1. FIG.
7 is a transverse plan view of a cooling device for a water-cooled internal combustion engine according to an embodiment (Embodiment 2) of the invention described in claim 3 of the present application, and is the same view as FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Water-cooled internal combustion engine, 1a ... Internal combustion engine main body, 2, 3 ... Crankcase, 4 ... Cylinder block, 5 ... Cylinder head, 6 ... Cylinder head cover, 7 ... Cylinder hole, 8 ... Piston, 9 ... Crankshaft, 10 ... piston pin, 11 ... crank pin, 12 ... connecting rod, 13 ... combustion chamber, 14 ... intake port, 15 ... exhaust port, 16 ... intake valve, 17 ... exhaust valve, 18 ... camshaft (camshaft), 19 ... Bearing, 20 ... Camshaft holder, 21 ... Drived sprocket, 22 ... Drive sprocket, 23 ... Endless chain (transmission mechanism), 24 ... Permanent magnet, 25 ... Idle sprocket (idle pulley), 26 ... Pin, 27, 28, 29 ... idler sprocket, 30 ... radiator, 31, 32 ... cooling water tank, 33 ... radiation fin, 34 ... cooling water conduit, 35 ... cooling water access opening, 36, 37 ... flange, 38 ... connection , 39 ... cap, 40, 41 ... radiator support, 42, 43 ... cooling water passage, 44, 45 ... cooling water jacket, 46 ... communication pipe, 47 ... bolt, 50 ... magnet coupling type cooling water pump, 51 ... partition wall (pump casing), 52 ... pump cover, 53 ... rotating shaft, 54 ... impeller, 55 ... permanent magnet, 56 ... suction part, 57 ... discharge part, 58 ... discharge passage, 59, 60 ... communication passage, 61 ... Communication pipe, 62 ... Transmission mechanism chamber, 63 ... Hole, 64 ... Communication pipe equivalent part.

Claims (5)

A cam shaft for driving the valve mechanism of the internal combustion engine is disposed above the cylinder head. The cam shaft is rotationally driven from the crankshaft through the transmission mechanism, and is cooled to the outside of the transmission mechanism chamber including the transmission mechanism. In a cooling device for a water-cooled internal combustion engine having a cooling water passage through which cooling water flows by driving a water pump ,
Said communicating pipe leading to the internal combustion engine body from the cooling water passage is arranged so that entrained the transmission mechanism compartment,
A cooling apparatus for a water-cooled internal combustion engine , wherein an idle pulley that is hung on the transmission mechanism is rotatably fitted and supported on an outer peripheral portion of the communication pipe . A cam shaft for driving the valve mechanism of the internal combustion engine is disposed above the cylinder head. The cam shaft is rotationally driven from the crankshaft through the transmission mechanism, and is cooled to the outside of the transmission mechanism chamber including the transmission mechanism. In a cooling device for a water-cooled internal combustion engine having a cooling water passage through which cooling water flows by driving a water pump,
The communication pipe from the cooling water passage to the internal combustion engine main body is arranged so as to be spanned over the transmission mechanism chamber,
On the outer periphery of the communication pipe, an idle pulley that is hung on the transmission mechanism is rotatably fitted and supported,
The transmission mechanism is an endless transmission mechanism,
The cooling device for a water-cooled internal combustion engine, wherein the cooling water pump and the cooling water passage are arranged in a region surrounded by the endless transmission mechanism . The cooling apparatus for a water-cooled internal combustion engine according to claim 1 or 2 , wherein an idle pulley that is hung on the endless transmission mechanism is disposed in the vicinity of the communication pipe . The cooling water pump is a magnet coupling type cooling water pump,
Communicating pipe to form a multiply passed passageway to said transmission mechanism chamber, according to any one of claims 1 to 3, characterized in that formed in the partition integral with the magnet coupling cooling water pump Cooling device for water-cooled internal combustion engine. The cooling water pump is a magnet coupling type cooling water pump,
Communicating pipe to form a multiply passed passageway to said transmission mechanism chamber, claims 1 to 3, characterized in that the partition wall of the magnet coupling cooling water pump is supported by the wall surface of the cylinder head The cooling device for a water-cooled internal combustion engine according to any one of the above.

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